1. Field of the Invention
This document relates to a display apparatus, and more particularly to, a plasma display apparatus and a method of driving the same.
2. Description of the Background Art
A plasma display apparatus comprises a plasma display panel for displaying an image and a driver for driving the plasma display panel. The driver is attached on a rear surface of the plasma display panel.
In the plasma display panel, a unit discharge cell is defined by barrier ribs disposed between a front substrate and a rear substrate. Each cell is filled with an inert gas containing a main discharge gas such as neon (Ne), helium (He) and a gas mixture of Ne and He, and a small amount of xenon (Xe). The plurality of discharge cells form one pixel. For example, a red (R) discharge cell, a green (G) discharge cell and a blue (B) discharge cell form one pixel.
When the inert gas is discharged due to a high frequency voltage, the inert gas generates vacuum ultraviolet rays, so that the rays excite and radiate a phosphor formed between the barrier ribs, thereby displaying an image.
The plasma display panel comprises a plurality of electrodes, for example, a scan electrode, a sustain electrode and an address electrode. Drivers for supplying a driving voltage to each of the scan, sustain and address electrodes of the plasma display panel are connected to the scan electrode, the sustain electrode and the address electrode, respectively.
When driving the plasma display panel, the drivers supply a reset pulse in a reset period, a scan pulse in an address period, and a sustain pulse in a sustain period to the scan, sustain and address electrodes of the plasma display panel, such that the image is displayed. Since the above-described plasma display apparatus can be manufactured to be thin and light, the plasma display apparatus has been considered as a display apparatus.
In the related art plasma display apparatus thus driven, image sticking occurs on the screen due to various factors affecting the discharge of the plasma display panel such as the phosphor.
FIG. 1 illustrates image retention generated in a related art plasma display panel.
As illustrated in (a) of FIG. 1, a discharge is locally generated in a predetermined portion 12 of a display surface 10 of the plasma display panel. As illustrated in (b) of FIG. 1, when the generation of the discharge in the predetermined portion 12 stops or a different image is displayed, the predetermined portion 12 is considered as image retention of a next image.
When the same image is continuously displayed or a change in an image is little, the image retention is seriously generated. For example, when there is no change in image data that is continuously input, or a rate of change in image data is equal to or less than a threshold rate of change of image data, the sustain pulses with the same pattern or similar pattern are applied within the discharge cell. Therefore, the state of the wall charges distributed within the discharge cell is fixed. Further, the various factors affecting the discharge such as the phosphor greatly affect the image sticking. As a result, an image directly before a fixed image pattern is displayed on the display surface 10 as image retention of a next image, thereby increasing image sticking.
With a recent tendency of the plasma display apparatus to achieve high brightness, for example, there is a method in increasing a peak voltage of the sustain pulse. However, a strong discharge is required to increase the peak voltage of the sustain pulse, thereby exciting a large amount of the phosphor. As a result, the various factors affecting the discharge such as the phosphor greatly affect the image sticking.